Features: Works with most pedometers, Smartphones (Under 6.4 inch) and Smartwatches. USB cable and battery dual-use model with metal brackets, very wear-resistant, long service life. After the product is assembled, the metal counterweight beads are stuck at the back, power is turned on, the mobile phone is put on, and the mobile phone can be moved once to achieve the physical shaking step. Automatic Step Earning Device: Suitable for those who want to increase the number of walks. High-quality metal brackets are smooth and burr-free, will not scratches hand and phone, low noise, will not affect sleep when shaking at night. Specifications: Material:ABS,Metal Size:Approx.10.8x19cm/4.25''x7.48'' Powered by:USB Cable or 4x AA-Battery(battery not inclued) Note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Mobile Phone Shaker